1. Field of the Invention
The present invention relates to a portable device having display means such as a liquid crystal display (LCD), and more particularly, to a portable device having limited display size and number of input keys.
2. Description of the Related Art
As the size of portable devices such as mobile telephones or compact disk players (CD players) has been reduced, the number of input keys and the display size of these devices has decreased. However, the memory capacity of the portable devices has increased and the functionality of the portable device has improved.
An example of a portable device having a limited display size and number of input keys is a compact disk (CD) player or an MPEG audio layer 3 (MP3) player that stores and reproduces audio files. The CD player reproduces the files stored in a CD, which is a kind of optical disk, and the MP3 player reproduces the MP3 music file, which is a kind of high quality audio compressing technology.
A CD-ROM used in the CD/MP3 combination player can store about 640 Mbytes of MP3 files. When the size of one MP3 type song is assumed to be 4 Mbytes, about 150 songs can be stored in one CD-ROM. Moreover, according to development in the compressing technology of the music file, if the size of one MP3 type song is further reduced to one third of the assumed 4 Mbytes, about 400 songs can be stored in one CD-ROM.
When several hundreds of songs are stored in one CD-ROM, it can be difficult to select songs by using only forward and backward keys. To solve this problem, the function of selecting ten songs by using one key has been introduced; however, considerable effort and time can still be needed for selecting one song.
An excessive increase in the limited number of input keys is prohibited by the small size of the portable devices. Therefore, a need exists for an efficient means of searching and selecting a song by inputting the title of the song in the portable device is needed.